Abstract: A novel spiroquinone derivative having a high ABCA1 stabilization effect and being useful for prophylactic and/or therapeutic agents for various diseases developing hypo-high density lipoproteinemia is obtained. The novel spiroquinone derivative is a compound represented by the following formula: wherein R1a, R1b, R1c and R1d each represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, or an alkoxy group which may have a substituent, and R2a and R2b each represents a hydrogen atom, or an alkyl group which may have a substituent (e.g.

Abstract: A novel spiroquinone derivative having a high ABCA1 stabilization effect and being useful for prophylactic and/or therapeutic agents for various diseases developing hypo-high density lipoproteinemia is obtained. The novel spiroquinone derivative is a compound represented by the following formula: wherein R1a, R1b, R1c and R1d each represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, or an alkoxy group which may have a substituent, and R2a and R2b each represents a hydrogen atom, or an alkyl group which may have a substituent (e.g.

Abstract: To provide a pharmaceutically effective prophylactic/preventive agent for low-HDL cholesterolemia, focusing on an HDL-generating mechanism. The ABCA1 stabilizer of the present invention contains a bisphenol-type compound selected form probucol spiroquinone, probucol diphenoquinone, and probucol bisphenol as an effective ingredient. The ABCA1 stabilizer can continuously and stably express ABCA1 by a mechanism quite different from that of conventional processes, and thus is useful as prophylactic/preventive agent for low-HDL cholesterolemia or arteriosclerosis.